Sweetcorn · Kolpino, St.-Petersburg, Russia
When to plant sweetcorn in Kolpino
Main outdoor window
9-23 Jun
A climate estimate. Check your soil, forecast and cultivar.
Timed from last spring frost
5 May
In Kolpino, on your chosen risk.
Ready to pick
8 Aug - 17 Sep
If you plant at the start of the window.
The average last frost. Half of all years are later than this.
Step by step in Kolpino
Download these planting dates (.ics)
Import into Apple Calendar, Google Calendar or Outlook. Dates use the selected risk level and are planning estimates, not frost alerts.
Each window is a planning range. Check the forecast, soil and cultivar before planting; a later date is not automatically safer in hot or wet conditions.
Sow direct
9-23 Jun
Delayed by a soil-warming estimate derived from historical air temperatures. The frost-only date would be 12 May. Measure your soil before planting.
Harvest
8 Aug - 17 Sep
Sweetcorn through the year
Against the frost risk in Kolpino
Seasonal context
Rainfall and the growing season in Kolpino
July has the highest average precipitation (98 mm); February has the lowest (41 mm). Compare this pattern with the planting windows and your water supply.
During wetter months, check that beds and containers drain after heavy rain. During drier months, plan how you will keep seeds and new transplants watered. Monthly averages can hide long dry spells and intense storms; they do not show soil moisture, humidity or this week's weather.
Source: NASA POWER, corrected MERRA-2 precipitation, 2001–2020. Values are approximate monthly totals, including the water equivalent of snow, from the nearest 0.5° × 0.625° grid cell. This reference period differs from the temperature record. Rainfall provides context and does not change the calculated planting dates. Method and limitations.
Monthly growing conditions in Kolpino
Compare the planting window with the local temperature pattern. These are historical monthly averages, not this year's forecast or measured soil temperatures. Average frost days do not tell you whether a particular night will freeze.
| Month | Average low | Average high | Frost days |
|---|---|---|---|
| January | -12°C (10.4°F)10.4°F (-12°C) | -6.8°C (19.8°F)19.8°F (-6.8°C) | 30.3 |
| February | -11.5°C (11.3°F)11.3°F (-11.5°C) | -5.5°C (22°F)22°F (-5.5°C) | 27.5 |
| March | -6.6°C (20.2°F)20.2°F (-6.6°C) | -0.5°C (31.2°F)31.2°F (-0.5°C) | 29.1 |
| April | -0.1°C (31.8°F)31.8°F (-0.1°C) | 7.6°C (45.6°F)45.6°F (7.6°C) | 16.0 |
| May | 5.7°C (42.3°F)42.3°F (5.7°C) | 14.4°C (58°F)58°F (14.4°C) | 2.3 |
| June | 11.2°C (52.1°F)52.1°F (11.2°C) | 19.1°C (66.5°F)66.5°F (19.1°C) | 0.0 |
| July | 14.1°C (57.5°F)57.5°F (14.1°C) | 21.7°C (71°F)71°F (21.7°C) | 0.0 |
| August | 12.8°C (55°F)55°F (12.8°C) | 20.2°C (68.4°F)68.4°F (20.2°C) | 0.0 |
| September | 8.2°C (46.8°F)46.8°F (8.2°C) | 14.9°C (58.7°F)58.7°F (14.9°C) | 0.0 |
| October | 2.6°C (36.7°F)36.7°F (2.6°C) | 7.2°C (44.9°F)44.9°F (7.2°C) | 8.3 |
| November | -3.6°C (25.4°F)25.4°F (-3.6°C) | 0°C (32°F)32°F (0°C) | 21.2 |
| December | -9.2°C (15.5°F)15.5°F (-9.2°C) | -4.6°C (23.7°F)23.7°F (-4.6°C) | 29.0 |
For sweetcorn, also check drainage, sunlight and cultivar requirements. See the rainfall context above; humidity, irrigation and local pest pressure are not calculated.
Local growing check
Before choosing sweetcorn for Kolpino
- July is the wettest month in the rainfall grid, averaging about 98 mm. Check how your own bed drains and plan watering around actual soil moisture; monthly rain totals are not an irrigation schedule.
The temperature and rainfall tables on this page show the underlying climate estimates. How these suitability checks work · Record what happens in your garden.
Before you plant sweetcorn
Use the calendar to plan ahead, then check the conditions in your own garden.
- Measure the soil at sowing depth. Aim for at least 15°C (59°F); the calendar estimates soil warmth from air temperatures and cannot measure your bed.
- Check the local overnight forecast before planting out. Delay planting or keep protection ready if frost is forecast, even after the historical last-frost date.
- Use the maturity range on your seed packet when choosing a variety. Cold, short days and transplant stress can make harvest later than the calendar estimate.
Plan for pollination as well as warmth
Plant a block rather than one long, isolated row to help wind pollination. Poorly filled cobs can be a pollination problem even when the plants look vigorous.
Read the seed supplier’s isolation advice when mixing sweetcorn types. Cross-pollination between incompatible types can change eating quality.
Keep water available during establishment and cob development. Harvest at the variety’s eating stage and use promptly; days-to-maturity figures are a guide, not a guarantee that every cob is ready.
Growing in a container
A single small pot is a poor setup for a full crop. Plan enough plants and root space for effective pollination, or use a bed.
Further reading: RHS sweetcorn growing guide . General crop guidance; local dates on this site are calculated separately. Source checked 18 September 2026 by Safe to Plant; this is not an expert review.
How the dates are calculated and their limits · Keep a growing record · Report a local discrepancy
Why these dates
Plant a block rather than one long, isolated row to help wind pollination. Poorly filled cobs can be a pollination problem even when the plants look vigorous.
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.
This calendar uses frost-relative offsets as a starting point. Sweetcorn are timed for direct sowing 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Kolpino.
The calendar also applies a soil-warming estimate derived from historical air temperatures. Where that estimate is later than the frost-based date, it delays the window. Soil in your own garden can warm earlier or later; a thermometer at sowing depth is a better final check. Cold, wet conditions can slow germination and increase decay risk.
The median frost-free season here is 163 days, against 60 to 100 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Nearby
Sweetcorn in places close by
Also in Kolpino
Other vegetables to time
Growing sweetcorn in Kolpino
Can I grow sweetcorn in Kolpino?
The calendar estimates a planting window, not a guarantee of success. July is the wettest month in the rainfall grid, averaging about 98 mm. Check how your own bed drains and plan watering around actual soil moisture; monthly rain totals are not an irrigation schedule.
When should I plant sweetcorn in Kolpino?
Aim for 9-23 Jun in an average year. If you would rather not gamble on the weather, wait until 9-23 Jun - by then frost has finished in nine years out of ten.
Can I plant sweetcorn earlier in Kolpino?
The historical frost estimate is 12 May. For Sweetcorn, an air-temperature model estimates soil warmth of about 15°C (59°F) around 9 Jun. This is not a soil measurement or a forecast. Check your bed at sowing depth; cold, wet conditions can slow growth and increase decay risk.
When might sweetcorn be ready to harvest in Kolpino?
The estimated period is 8 Aug - 17 Sep, based on 60 to 100 days from the modeled planting date. Cultivar, planting material and growing conditions can change this interval; check the plant as well as the calendar.
How much frost will sweetcorn tolerate?
Check the named variety and local forecast before exposing young growth. The catalog cold-damage figure is a reference, not a guarantee: plant age, acclimatisation, wind and the duration of a freeze affect damage.